I Don't Know What To Play Vs. 1.d4

Perhaps the most common opening struggle for chess players is: 'What do I play against 1.d4?'

Even a lot of advanced players struggle to settle on a long-term defence to 1.d4 that they are happy with.

That's why I recorded a video detailing the pros and cons of each option against 1.d4 (typically followed by 2.c4), so that you can make an informed decision for your situation:

You will also find this video very useful if you play 1.d4 as White, as I show you what I consider the most annoying lines for White in each of the major systems! 

Remember, if you are rated 2000+ and want to become a chess master more quickly, you can connect with me at http://m.me/max.illingworth.16

For those who want to quickly see how your current defence to 1.d4 compares with the other options, I've written an overview below, listing the openings in ascending order of strength; enjoy!

The Sidelines vs. 1.d4

1...e5?? - 2.dxe5 and White is winning.

1...b6? - 2.e4 Bb7 3.Bd3 +/-

1...c5? - 2.d5 Nf6 3.Nc3! is the problem, typically transposing to the Schmid Benoni after 3...d6 4.e4 g6 which is well known to be +1 according to modern engines (like 1...b6).

Iljin-Zhenevsky (Classical) Dutch - 1...f5?! 2.g3 Nf6 3.Bg2 e6?! 4.c4 Be7?! 5.Nf3 0-0 6.0-0 d6 and now White can play 7.b3! (see diagram below) to dodge the Williams idea of 7.Nc3 Ne4 for a clear advantage. 

1...g6?! - This Modern approach actually works well if White sticks to c4 territory, as after 2.c4 Bg7 3.e4 d6 4.Nc3, Black can (and objectively, should) transpose to the King's Indian with 4...Nf6. However, if White has the flexibility to play 1.e4 as well as 1.d4, then 2.e4! Bg7 3.Nc3 d6 4.Be3 gives White close to a clear advantage. I admitted as much in my recent course 'Play 1...g6 Like Hikaru'. 

Stonewall Dutch - 1...f5?! 2.g3 Nf6 3.Bg2 e6?! 4.c4 d5 is at least not a system that can be clearly refuted, as is the case with the previous systems. Nonetheless, it's quite passive and White has many paths to a pleasant (~0.5) advantage, from flexible Nh3-based setups to 5.Nf3 Bd6 6.0-0 c6 7.Ne5!? (a recent preference of NNUE engines) or one of the more classical main lines. 

Leningrad Dutch - 1...f5?! 2.g3 Nf6 3.Bg2 g6! - to be fair, the Dutch is not 'that' bad, and the Leningrad has generally held its own in strong correspondence play. However, it requires a much higher level of precision than the next openings we'll see. For instance, in the main line 4.Nf3 Bg7 5.0-0 0-0 6.c4 d6 7.Nc3, only 7...c6! limits White to a small advantage. 

1...d6?! - This 'Rat' move order creates interesting possibilities such as 2.c4 e5 (which is only slightly better for White if he's well-prepared) and 2.Nf3 Nf6 3.c4 g6 4.Nc3 Bf5? (which admittedly doesn't hold up to closer scrutiny). 

However, the real issue with this move order, like we saw with 1...g6 before, is 2.e4! Nf6 3.Nc3, when neither the Pirc (3...g6) or Philidor (3...e5) bring Black anywhere near equality (+0.5). 

1...e6 - the main objective disadvantage of this move is that it allows a transposition to the French with 2.e4, which is only the 4th best defence to 1.e4 (+= although it can be neutralized with extremely deep preparation). However, otherwise it usually ends up transposing to some main line when Black plays ...Nf6 or ...d5 next move. 

Independent tries tend to backfire against a well-prepared opponent, as 2.c4 Bb4 3.Bd2 a5 (for instance) gives White some promising independent tries to a Bogo-Indian transposition (such as 4.a3 or 4.Nc3 for +0.5), while the English Defence with 2...b6 is also significantly better for White after 3.e4.

Options Within 1.d4 d5 2.c4 (see diagram below)

Albin Counter-Gambit - 2...e5? is just a pawn blunder. 3.dxe5 d4 4.Nf3 Nc6 5.Nbd2! is +1. 

Chigorin - 2...Nc6?! at least doesn't blunder a pawn, but it's a clear strategic mistake to block the c-pawn this early, and White has many ways to achieve a +0.6 advantage or greater. It doesn't help that after 3.Nf3, the 'thematic' follow-up of 3...Bg4?! backfires to 4.cxd5 Bxf3 5.gxf3 Qxd5 6.e3 when the bishop pair and central majority give White a clear advantage. 

2...c5?! - this Austrian/Symmetrical Defence is not completely stupid, having been played by Mamedyarov in some quickplay games, but nonetheless 3.cxd5 Qxd5 4.Nf3 cxd4 5.Nc3 Qa5 6.Nxd4 gives White a free lead in development and a pleasant advantage (around +0.6). 

Tarrasch Defence - I neglected to cover this in the video, but the antidote for White is pretty well-known by now. Usually if Black plays the Tarrasch nowadays, it's to play the Dubov Variation with 2...e6 3.Nc3 c5 4.cxd5 exd5 (the Von-Hennig with 4...cxd4?! doesn't hold up to engine scrutiny) 5.Nf3 Nc6 6.g3 Nf6 7.Bg2 cxd4! 8.Nxd4 Bc5! (see diagram below), which indeed comes close to full equality for Black (+0.25). 

The problem is that White can avoid this quite easily with the stronger 6.dxc5! (+0.3), and the attempt to dodge this with 5...Nf6 runs into 6.Bg5!. 

Queen's Gambit Accepted - 2...dxc4 is a solid line that has held its own in correspondence, and is a recent favourite of Aronian. However, Black has to work harder to prove equality in these lines than some others we will see. For instance, in the modern main line of 3.Nf3 Nf6 4.e3 e6 5.Bxc4 c5 6.0-0 a6 7.dxc5, White achieves a slightly more pleasant endgame (+0.3) where White must show some special talent to lose the game. 

White also has the more direct option of 3.e4, which Black can meet in a few ways, but whether he goes for the exchange sack line starting with 3...b5!? or the main line of 3...e5 4.Nf3 exd4 5.Bxc4 Nc6 6.0-0 Be6, he has to play a lot of precise moves to achieve a marginally worse but holding endgame. (OK, the 3...Nf6 line keeps more 'fight' over the long-term, but the lack of space gives White the much easier game)

Chebanenko Slav - this refers to the Slav with 2...c6, but in connection with ...a6. This is actually the most common line against the 'Modern Exchange Slav' move order 3.cxd5 cxd5 4.Bf4 Nc6 5.e3 Nf6 6.Nc3, where 6...a6 is initially considered slightly better for White by engines, but this gradually dissipates as Black continues to play the right moves. (6...Bg4/6...Bf5 is the 'clean' equalizer, for those who were wondering)

However, the Chebanenko setup tends to be a bit less effective in other lines - for instance, 3.Nf3 Nf6 4.Nc3 a6 5.c5! (see diagram below) gives White a pleasant space advantage (around +0.4).

...while 3.Nc3 Nf6 4.e3 a6 5.Nf3 is also thought to slightly favour White (albeit 'only' by about +0.35).

Main Line/Classical Slav - this refers to the 3.Nf3 Nf6 4.Nc3 dxc4 move order, typically followed by 5.a4 Bf5 which has quite a rich history. However, the Alekhine Variation with 6.Ne5! Nbd7 7.Nxc4 is well known to give White a small edge (+0.35) after either 7...Nb6 or the older 7...Qc7. 

Incidentally, White sometimes play 4.e3, the 'Slow Slav', to avoid such lines by Black (or to have extra options without Nc3 if Black plays the Semi-Slav with 4...e6). Then 4...Bg4 5.h3 is thought to slightly favour White, but 4...Bf5 5.Nc3 e6 6.Nh4 Bg6 or first 6...Be4 7.f3 Bg6 (see diagram below) are known to be very solid for Black.

Initially the engine gives +0.2 for White in such lines, but if one goes deep enough, it starts to head towards 0.00 territory. 

Note that I haven't included the Semi-Slav under 1...d5, as the top players typically reach this opening via. a 1...Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 c6 move order - more on that later.

Triangle System - This is the move order with 1.d4 d5 2.c4 e6 3.Nc3 c6, which is typically used to either transpose to a Semi-Slav with 4...Nf6 next move, or to play independently with something like the Noteboom (4.Nf3 dxc4), which has been worked out to a draw in correspondence, but over-the-board it's quite a bit harder to demonstrate than in some of the 'hardcore' main lines we'll see later. 

Of course, Black also has to be ready for the Marshall Gambit with 4.e4, which has been worked out to equality in some very forcing and long theoretical lines, but against a prepared opponent it may be difficult to win. Also, the Triangle is not necessarily an 'all in one' system, as after 3.Nf3 c6, White obtains promising extra options such as 4.e3 and 4.Nbd2 Nf6 5.g3, as the 'Stonewall' approach with ...f5 generally gives White a very nice advantage. 

Classical QGD - this refers to 2...e6 3.Nc3 Nf6 (we'll talk about 3.Nf3 Nf6 later), as the 'Alatortsev' move order of 3...Be7 gives White an improved Exchange Variation with 4.cxd5 exd5 5.Bf4. Speaking of which, the primary extra option for White in this move order (versus the 'Nimzo' move order we'll see later) is the Exchange Variation with 4.cxd5 exd5 5.Bg5.

Modern engines have come up with creative ways to neutralize White's initial pull, such as 5...c6 6.e3 h6! (thought to be an inaccuracy in the pre-computer era) 7.Bh4 Be7 8.Bd3 0-0 9.Qc2 Re8 and Black is ready to exchange the dark-squared bishops to liberate his position, with either 10.Nf3 Ne4! 11.Bxe7 Qxe7 or 10.Nge2 Nbd7 11.0-0 Nh5! 12.Bxe7 Qxe7 (see diagram below).

In both cases, we see the advantage of not losing a pawn to Bxh7+. Engines initially give White a very small edge (around +0.25), but this can be neutralized with quite natural moves. Nonetheless, this accurately reflects practical play, where White's position has proved significantly easier to play.

1.d4 Nf6 2.c4 Sidelines

In fairness, these next lines would be most appropriately 'ranked' with the 1.d4 Sidelines in the first section, but this order makes the most logical sense in terms of 1...Nf6 being Black's objectively best reply to 1.d4 (if we exclude using the 1...d5 move order to reach the Semi-Slav).

Budapest Gambit - 2...e5? is not technically a pawn blunder, but after 3.dxe5 Ng4 4.Nf3 (or other lines like 4.Bf4 or even the NNUE-style 4.e3 Nxe5 5.f4!), Black makes significant positional concessions, as reflected in the engine's +0.8 assessment. 

Black Knight's Tango - I used to have a soft spot for 2...Nc6?!, but it's just bad, and it doesn't help that after 3.Nc3, Black's best bet is to transpose to the Chigorin with 3...d5, as the thematic 3...e5 4.d5 Ne7 is effectively refuted by 5.Nf3! Ng6 6.h4! (+1.3).

Old Indian - I left out 2...d6 in the video as Black should subsequently transpose to the King's Indian with ...g6/...Bg7. If he plays ...Be7 or some other non-...g6 approach, he's clearly worse (at least +1 for White). 

Modern Benoni - 2...c5?! 3.d5 e6?! is not an annotation I enjoy making, but after 4.Nc3 exd5 5.cxd5 d6 6.e4 g6, White has some very good extra options without Nf3, the best of which is the Taimanov Attack with 7.f4! Bg7 8.Bb5!, forcing 8...Nfd7 when 9.a4! prevents any ...a6/...b5 counterplay to give White a clear advantage (the conservative claim is +0.7). 

Accelerated Queen's Indian - 2...b6?! isn't objectively better than 2...Nc6, but it's a little bit trickier, as after 3.Nc3 (or 3.f3!?) Bb7, White at least needs to know the move order subtlety of 4.Qc2! d5 5.cxd5 Nxd5 6.Nf3! (see diagram below) and only then e4 to get his +0.6 advantage - the point being that White is effectively a tempo up on the Petrosian Queen's Indian, having replaced a3 with Qc2. 

Benko Gambit - Perhaps I'm biased about 2...c5 3.d5 b5 due to playing it so much in online blitz, but at least White has to be more precise in this opening than the other ones I mentioned to get a +0.6 advantage. 4.cxb5 a6 5.e3 is one annoying line that convinced me to give up the opening, while 5.bxa6 works even better if Black sticks to the 'usual' set up with ...g6, as e.g. 5...g6 6.Nc3 Bg7 7.e4 0-0 8.a7! Rxa7 9.Nf3 (see diagram below) demonstrates.

Black doesn't have his standard ...Qa5 anymore because of Bd2!, and Nb5 subsequently hits both Black's queen and rook. 

The other reason the Benko ranks higher than the other 1.d4 Nf6 2.c4 sidelines I mentioned is because Black's objectively best move after 5.bxa6 is 5...e6, aiming for some Blumenfeld-style compensation, although it's not exactly in the original 'spirit' of the opening and is mainly a way to beg for a draw (+0.6). 

1.d4 Nf6 2.c4 g6 Systems (KID/Grunfeld)

King's Indian without the Mar del Plata - The King's Indian is possibly the most popular defence to 1.d4 at the 1600-2000 level, and indeed 1.d4 Nf6 2.c4 g6 3.Nc3 Bg7 4.e4 d6 5.Nf3 0-0 has the advantage that it can be played against almost anything other than 1.e4. The big question for a King's Indian player is - what should be played against the Classical Variation, 6.Be2 e5 7.0-0? (see diagram below)

I personally struggled to find a good answer to this question for myself. Black's best alternative to 7...Nc6 (see next heading) is probably 7...exd4, but in these lines, Black is basically playing only for equality (+0.5 according to engines, though +0.2/+0.3 is probably a more objective assessment), and his winning chances mainly come from White either overpressing or falling for a cheap trick. Other moves like 7...Na6 (+0.5) and the classical 7...Nbd7 (+1 - though the leading ...Nbd7 expert Jones recently made some arguments for this evaluation being too optimistic) give White a more pleasant advantage, objectively speaking.

King's Indian with the Mar del Plata - Naturally, Black's best move is 7...Nc6 8.d5 Ne7, and although engines initially love White's chances in the Bayonet (9.b4), in correspondence Black has shown that the initial 'clear advantage' engines give is very inflated after 9...Nh5, and that with very deep preparation, Black can maintain the balance. The main trend in modern GM play is 9...a5, as it requires a lot less memorization, though it does concede some objective advantage to White. 

Of course, even if one finds a satisfying line against the Classical, there are other potential problems, as Black has to be ready for the many options at White's disposal. Perhaps the most annoying of these is the Semi-Makogonov 5.h3 0-0 6.Be3, as Black doesn't have a clear route to equality after 6...e5 7.d5 (+0.5), but the potential Maroczy Bind transposition with 6...c5 7.Nf3 (+0.5, see diagram below) is also practically unpleasant.

...Even if in correspondence Black has found ways to hold the 'worse' (according to the computer) positions to a draw. There's also the solid Fianchetto Variation with 3.g3, but I'll discuss that under the 'Anti-Grunfelds'. 

Grunfeld

I personally consider the Grunfeld to be a 'cleaner' equalizer vs. 1.d4 than the King's Indian, but there are also some similar challenges, as after 3.Nc3 d5 there are a lot of options for White, and Black must be prepared for all of them. The current main trend is the Exchange Variation with 4.cxd5 Nxd5 5.e4 Nxc3 6.bxc3 Bg7 7.Nf3 c5 8.Be3, a very safe line where a good memory is essential to equalize as Black.

The old main line of 7.Bc4 is one where it's not easy to play for a win as Black at a high level, unless you're willing to play a slightly inferior variation. It's the same story with the less trendy 4.Bf4, at least in my experience, and the sidelines also require quite specific knowledge to neutralize.

Anti-Grunfelds

Granted, the Grunfeld is flexible enough that most 'drawish' lines can be avoided or at least spiced up, but that leaves the question of 'Anti-Grunfeld' lines such as the Fianchetto Variation, 3.g3. The main issue Black faces here is that the more dynamic lines (such as the ...Nbd7/...Nc6 King's Indian, ...d5 or early ...c5 approaches) tend to give White a pleasant advantage if he booked up with the engine.

However, the most solid line of 3...c6 4.Bg2 d5 (and also the ...c5 Yugoslav Variation of the King's Indian, see diagram below) leads to much more strategic, slower play than KID/Grunfeld players typically dream of, and White also has quite safe symmetrical approaches (dxc5 in the Yugoslav, cxd5 in the ...c6 lines) where Black must be both patient and a little creative to generate winning chances (but at least you get 0.00 equality if you go deep enough).

A more subtle point is that the Grunfeld isn't quite as effective against 1.Nf3/1.c4, so you'll need to research another line (likely within the Symmetrical English, 1.../2...c5) to avoid getting move ordered here. 

1.d4 Nf6 2.c4 e6 In The Hypermodern Style (Without 3...d5)

In this section, we're going to address the Nimzo-Indian and also the 3.Nf3 lines where Black is not ready to transpose back into the Queen's Gambit Declined with 3...d5. 

Aron Nimzowitsch

Nimzo-Indian (non-...d5 approaches) - one of the main attractions of 1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 is that it's very flexible, making it quite easy to find a way of playing it that fits with your style (as well as White scoring only 51% on average, well below the norm of 54% after 1.d4). Avoiding ...d5 works particularly well against the Samisch (4.a3 Bxc3 5.bxc3), so that after 5...c5 we can pile the pressure on the weak c4-pawn. Against 4.Qc2, the old main line of 4...0-0 5.a3 Bxc3 6.Qxc3 b6 (see diagram below) remains quite playable (+0.1).

Against the Rubinstein (4.e3), spurning the main line of 4...0-0 5.Bd3 d5 will give White decent chances of an advantage, e.g. 4...b6 5.Nge2! (+0.35) and 4...c5 5.Nge2! (+0.2) are both slightly better for White, whereas after 4.e3 0-0 5.Nge2, Black has many paths to 0.00-level equality (the main line 5...d5, but also 5...Re8 6.a3 Bf8 and even 5...c6!?). 

Nimzo-Indian (...d5 approaches) 

The classical approach to the Nimzo-Indian with ...d5 is the most reputable, and indeed, it is the 'Kramnik Variation' with 4.Qc2 0-0 5.a3 Bxc3 6.Qxc3 d5! (equally playable via. the 4...d5 5.a3 Bxc3 6.Qxc3 0-0 move order, if one doesn't mind 5.cxd5 exd5) that caused a significant hit in 4.Qc2's popularity. Sometimes White tries to avoid this with 4.Qc2 0-0 5.Nf3 or 5.e4, but these also come to 0.00. 

The old main line of the Rubinstein is 4.e3 0-0 5.Bd3 d5 6.Nf3 c5 7.0-0, when Black has several playable options, but the Karpov Variation with 7...dxc4 8.Bxc4 cxd4 9.exd4 b6 (see diagram below) is the cleanest equalizer (0.00), while keeping enough complexity with the IQP or hanging pawns (in the case of ...Bxc3) to play for a win.

That's why some top GMs are going for shortcuts like 5.Bd2, 4.f3 and so forth, but the majority prefer to just avoid the Nimzo altogether (see the next sections).

3.Nf3 c5 - As fun as the Blumenfeld (3.Nf3 c5 4.d5 b5) looks at first sight, it's a worse Benko and after 5.dxe6 fxe6 6.cxb5 White is basically up a pawn for nothing (+0.9).

As for the Modern Benoni, it's more respectable via. the 2...e6 3.Nf3 c5 4.d5 d6 5.Nc3 exd5 6.cxd5 g6 move order (and fully playable via. 2...e6 3.g3 c5 at around +0.3) as White is committed to Nf3. However, White still has promising options, such as 7.Nd2! Bg7 8.e4 0-0 9.Be2 Re8 10.0-0 (see diagram below), transposing to the Classical Variation where White has a very stable advantage (around +0.8). 

Bogo-Indian - When I first learned the Nimzo as Black, I accompanied it with 3.Nf3 Bb4, as a 'lazy' way to implement a dark-squared centre with 4.Bd2 Qe7 followed by a later ...d6/...e5.

However, the Catalan approach with 5.g3 gives White a nice advantage (at least +0.4), and Black's other replies to 4.Bd2 also give White a small advantage (the engine recommends 4...Bxd2 at +0.35, but this is a 'beg for a draw' line). There's also the issue of 4.Nbd2, intending 4...0-0 5.a3 Be7 6.e4 with a pleasant space advantage more or less for free. 

Classical Queen's Indian with ...Bb7 - The Queen's Indian is the 'natural' hypermodern complement to the Nimzo-Indian, but despite the Hiarcs Book claim that 3...b6 is equivalent to 3...d5, I always felt that White's position is both easier to play and objectively a little better - although that's not the case for the Petrosian Variation, 4.a3 Bb7 5.Nc3 d5, which is balanced (0.00). 

The big challenge is 4.g3!, and the old-school approach of 4...Bb7 5.Bg2 Be7 (more solid than ...Bb4 lines) 6.0-0 0-0, while very safe, is perhaps not the most suitable in a must-win game. The main line of 7.Nc3 Ne4 8.Bd2 (see diagram below), keeping the tension for a +0.3 advantage according to the computer, seems the most promising direction, even though the computer tends to slightly over-rate White's space advantage in such positions (a bit like in the King's Indian). 

Modern Queen's Indian with ...Ba6 - The 4.g3 Ba6 variation, by contrast, requires much deeper and broader theoretical knowledge, but the reward is better chances to equalize out of the opening, as White's alternatives to 5.b3, while initially attractive to the machines (+0.2), ultimately peter out to equality in the end. 

As for the main line 5.b3 Bb4 6.Bd2 Be7 (to lure White's bishop away from the Bb2 fianchetto), the trend has shifted away from the old main line of 7.Bg2 c6, which gives a small but risk-free edge for White (+0.2). Instead, Black usually goes for the strategic 7...d5 these days (also against the 'anti-...c6' move order of 7.Nc3), as after 8.cxd5 exd5 9.0-0 0-0 10.Nc3 Re8, it's not easy for White to translate his central majority into a more tangible advantage (+0.15). 

The Improved Queen's Gambit Declined (Nf3/Nf6) Without 4.Nc3

To be clear, this refers to the 1.d4 Nf6 2.c4 e6 3.Nf3 d5, which is the main repertoire of most of the top GMs against 1.d4. However, the way in which they interpret the play from here varies. 

The Lame Exchange - I added this section for those who don't understand the difference between 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5 and 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.cxd5 exd5. The key is that, in the latter case, White has played Nf3 too early, and this allows Black to develop his bishop to f5 without consequence.

Concretely, 5.Nc3 c6 6.Bg5 h6 7.Bh4 Bf5! allows Black to immediately liberate his bishop for clear equality, although the main line of 6...Be7 7.Qc2 g6 8.e3 Bf5 also achieves this objective. Compare this with  the Short Variation, 1.d4 d5 2.c4 e6 3.Nc3 Nf6 4.cxd5 exd5 5.Bg5 c6 6.e3 Bf5 7.Qf3! (+0.4, see diagram below), where Black is basically begging for a draw. 

The Catalan (Introduction) - One unique characteristic of the Catalan (1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.g3) is that Black has many equivalent replies to this opening, but in all cases, White has a flexible, solid position with ways to try and establish long-term positional players. This is possibly why Avrukh recommended this in his revolutionary 'Grandmaster Repertoire - 1.d4' series of books for White, and it would be fair to call the Catalan 'The Ruy Lopez of 1.d4' for its strategic richness. 

Now let's weigh up the strength of Black's options vs. the Catalan, in rough ascending order.

The Closed Catalan with ...Be7 - I personally find the 'automatic' setup with 4...Be7 5.Bg2 0-0 6.0-0 c6 (or 6...Nbd7) a bit too passive - if White is able to get in 7.Qc2 Nbd7 8.Nbd2 b6 9.e4, his space advantage gives him a pleasant pull (+0.25, but only if Black knows the Ntirlis recommendation of 9...dxc4!). These days White often prefers setups such as 6...c6 7.Qc2 b6 8.b3, also with a small advantage (+0.3). 

The Open Catalan - Those who like more direct play will probably favour 4...dxc4, but after 5.Bg2 Black has a broad choice (see diagram below).

The more solid approaches are to play 5...Bb4 6.Bd2 a5 or the central 5...c5 6.0-0 Nc6, in either case with a +0.25 advantage for White that can, admittedly, be neutralized with thorough preparation.

However, the main line is 5...a6 6.0-0 Nc6 (to avoid 5...Nc6 6.Qa4!), a line that engines initially give as better for White after 7.e3. However, instead of the correspondence solution of 7...Bd7 8.Qe2 Bd6 9.Qxc4 0-0 (which is a fair bit easier for White in practical play), the modern trend of 7...Rb8 8.Nfd2 e5! is a sharp pawn sacrifice that ultimately comes to equality after some very sharp and long-winded engine variations.

Of course, White has alternatives to 7.e3, but then Black equalizes more easily than in the main line.

The Open Catalan With 4...Be7 - If Black wants to play 4...Be7 against the Catalan, the best way to do so is 5.Bg2 0-0 6.0-0 dxc4, releasing the tension so that after 7.Qc2 a6 (more reliable than Nepo's sharper 7...b5 from the World Championship Match) 8.Qxc4 b5 9.Qc2 Bb7, Black is able to counteract White's 'Catalan' bishop on g2 for equality (0.00). 

That's why the main trend is instead 8.a4, stopping ...b5 so that Black must settle for the more awkward 8...Bd7 9.Qxc4 Bc6 to challenge White's g2-bishop. White usually opts for 10.Bg5 (see diagram below),

...When White's central majority gives him some hopes for an edge or at least to outplay the opponent, but the b4-square often proves a weakness for White, while Black's position remains stable with no weakness (+0.10), making this a popular opening for both sides at the super-GM level.

The ...Bb4 Closed Catalan - This refers to the 4...Bb4 variation, with the idea that after 5.Bd2 Be7 (more reliable than the Ukranian Variation, 5...Bd6), the White bishop is misplaced on d2, so that after 6.Bg2 0-0 7.0-0 Nbd7 8.Qc2 c6, White is unable to play for Nbd2/e4 without first moving the bishop from d2. This subtle difference shifts the assessment from += to the better side of equality (+0.10). 

However, there is one move order point Black needs to appreciate - if White plays 3.g3 d5 4.Bg2, this gives him the extra option of 4...Bb4 5.Nd2 0-0 6.Ngf3 (see diagram below), a line in which Carlsen has lost several times, despite trying both the Queen's Indian transposition of 6...b6 7.0-0 Bb7 (the main line) and the pawn grab 6...dxc4 (the main alternative).

That said, these lines are objectively equal (0.00 after a deeper analysis), and can also be avoided with the 3...Bb4 4.Bd2 Be7 5.Bg2 d5 move order. That's because 4.Nd2 gives Black the extra possibility of 4...c5 5.a3 Bxd2 6.Qxd2 cxd4, when Black's lead in development fully compensates White's bishop pair (0.00).

The Improved Queen's Gambit Declined Main Line 4.Nc3

While it was very interesting to explore the Catalan possibilities in depth (including, some concepts I didn't appreciate when I was an IM struggling against this opening), the main line is 4.Nc3, giving Black a wide choice of options.

Note that the 4.Bg5 move order is less precise because of 4...dxc4!, when 5.Nc3 a6! is an improved Botvinnik Semi-Slav for Black, but other tries like 5.e4 and 5.Qa4 are more creative offshoots (in the spirit of Mamedyarov and Dubov) than real attempts at an advantage. 

4...h6?!/4...a6?! - Such pawn moves may seem ridiculous, but both have been used on multiple occasions by Carlsen, albeit mainly in rapid/blitz. Admittedly, 4.Nc3 h6 feels rather wasteful after 5.g3, but 4...a6 is quite a respectable shortcut, albeit not one that fully equalizes after 5.cxd5 exd5 6.Bg5 Be6 7.e3 Nbd7 8.Bd3 (see diagram below).

Or, if White wishes to avoid 8...h6 9.Bf4 g5 10.Bg3 Nh5 (+0.4), 8.h3!?. White can also play super safely with 5.c5, which is objectively not as strong (+0.25), but may put off some from using 4...a6 as a winning try. 

It's worth noting that Black could also play the ...a6 systems via. the Janowski move order, 1.d4 d5 2.c4 e6 3.Nc3 a6. This can transpose after 4.cxd5 exd5 5.Nf3 Nf6, or be played independently with 5...c6, which may be objectively the better option (+0.30). Still, White can also vary, and 5.Bf4 is a popular independent option that's been scoring heavily for White in recent GM games (+0.25).

4...Nbd7 - This move is mainly used to transpose to other lines, such as the Exchange Variation with 5.cxd5 exd5 6.Bg5 (albeit with White committed to Nf3) or the Classical QGD, Kramnik Variation after 5.Bg5 h6 6.Bh4 Be7 7.e3 0-0, where White has failed to prove any realistic advantage.

This move used to be considered inferior because of the Blackburne-style 5.Bf4, but in recent years Black came up with the inspired 5...dxc4 6.e3 b5!, sacrificing a pawn to take back the initiative after 7.Nxb5 Bb4 and ...Nd5. Admittedly, this line is now considered more of a drawing weapon (+0.25), which is perhaps why 4...Nbd7 is not that trendy lately, but there's nothing wrong with the move per se. 

The Classical Approach - I am referring to 4...Be7 here, and you may be surprised to see the main line of the pre-computer era ranked this 'low' in the rankings of Black's options. Granted, you don't see the old main line of 5.Bg5 much at high level anymore, as after 5...h6 6.Bh4 0-0 7.e3, Black can either equalize comfortably with 7...Ne4 (the Lasker) or have good chances to outplay the opponent in a totally balanced position with 7...b6 (the Tartakower).

The real practical problem is the Blackburne with 5.Bf4! 0-0 6.e3 (see diagram below), when Black can gradually equalize with very good preparation, but it's not the most pleasant task.

Usually the most Black can hope for in lines such as 6...c5 (+0.25) or 6...Nbd7 7.c5 (+0.20) is a draw (though of course, he has excellent chances to achieve it). White also has very safe alternatives such as 6...Nbd7 7.Be2 or even 7.a3, where again Black has to be comfortable holding a slightly passive position (+0.1) without a lot of winning chances. 

The Vienna - 4...dxc4 is not one of the most common moves, but it's quite a popular recommendation in recent repertoire works as a viable shortcut, especially since the old main line of 5.e4 Bb4 6.Bg5 (often reached via. a Ragozin move order with 4...Bb4 5.Bg5 dxc4 6.e4) has largely been worked out to a draw by engines after 6...c5 (though Vienna experts Aronian and So will vary with the slightly inferior 6...b5 or the practically more difficult 6...h6!? respectively, when playing for a win). 

That's why the main trend is the Vienna Gambit with 6.Bxc4! Nxe4 7.0-0, which gives White an early initiative, though it can be neutralized with precise, engine-like defence after 7...Nf6 (or 7...Nxc3 8.bxc3 Bd6). In turn, the last 5 years saw the birth of a totally new interpretation by Black in 5...b5!? 6.e5 Nd5 7.Nxb5 Nb6, returning the pawn but creating an irrational position where the c4-pawn is not as weak as it first seems. This is a very hot line where White has not yet found a way to translate the engine's favourable assessment (+0.3) into a durable, long-term advantage.

The Semi-Tarrasch - I'm referring to 4...c5, which has recently undergone a revival as the 'Berlin' equivalent vs. 1.d4. This is not because of the old main line 5.cxd5 Nxd5 6.e4 Nxc3 7.bxc3 cxd4 8.cxd4 Bb4 9.Bd2 Bxd2 10.Qxd2 0-0 (though even here Black is fine, +0.1), but rather, the modern 5...cxd4! 6.Qxd4 exd5 (see diagram below).

White has failed to prove any advantage either in the endgame after 7.e4 dxe4 (+0.1), or in the IQP middlegame of 7.Bg5 (+0.1).

This is the reason many players transpose to the 'old' Semi-Tarrasch with 5.e3 for a fighting position, likely with an IQP for one player. That can happen in the 'Reversed Panov' form with 5...Nc6 6.cxd5 exd5 7.Bb5 cxd4 (0.00), or in the case of 6...Nxd5 (as could happen also via. the 5.cxd5 Nxd5 6.e3 Nc6 move order) 7.Bd3 Be7 8.0-0 0-0, White will likely get the IQP (also 0.00). Such lines are why top players can no longer rely on a narrow White repertoire for success, as even when you play the main lines, Black can bring it down to 0.00 by diving deep enough with the engine. 

The Ragozin - 4...Bb4 is a very active move that is the favourite of Leela Zero, as well as many of the world's top players (Nepomniachtchi, Ding, Aronian and many others).

I ranked it above 4...c5 not for objective reasons, but because these positions are quite rich and flexible, giving more winning chances for Black in general. In the 5.Bg5 main line, Black could transpose to the Vienna with 5...dxc4 (as noted before), but also 5...h6 6.Bxf6 Qxf6 is super solid for Black, with the bishop pair vs. space imbalance giving chances for the better player to show their superiority. 

Given that 5.cxd5 exd5 6.Bg5 has also proven to be a dead end for White, because of 6...h6 7.Bh4 0-0 8.e3 Bf5, White sometimes plays sidelines to try and catch Black out, and the main attempt lately has been with 5.Qa4 Nc6 6.e3 0-0 7.Qc2 (see diagram below).

This is a more strategic line where Black provokes the ...Nc6 move to avoid Black's freeing ...c5 break. But the engine also gives +0.00 here after 7...Re8, so we can say that the Ragozin is in excellent health and shows no signs of slowing down. 

Nonetheless, there is one system left, that I consider the 'ultimate' defence to 1.d4, in terms of giving the best of each of the following elements:

- Objective Strength;

- Solidity;

- Winning Chances;

- Counterattacking Potential;

- Flexibility Of Options.

And that system is...

The Semi-Slav

In fact, I recorded a video a couple of months ago explaining why I respect the Semi-Slav so highly, as well as showing the main options for Black and the pros and cons of the different move orders. You can watch it below:

For our purposes, I'm using the 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 c6 move order, though I noted earlier in this post that 1.d4 d5 2.c4 c6 3.Nf3 Nf6 4.Nc3 e6 (Slav) and 1.d4 d5 2.c4 e6 3.Nc3 c6 and 4...Nf6 (Triangle) are two other move orders that are in no way inferior to the 'Nimzo' movve order, objectively speaking. Since 5.cxd5 exd5 transposes to the 'Lame Exchange', let's dive into the main tries:

5.e3 Alternatives - If Black wishes to reduce his workload in playing the Semi-Slav, there are shortcuts at his disposal. One example is to meet 5.e3 with 5...a6, although this does give White the extra option of 6.b3 for a small advantage (+0.25). Another instance is 5...Nbd7 6.Qc2 b6, as recently played by Carlsen in Tata Steel 2022, which gives White more chances of an advanage (+0.25), but is a playable and solid shortcut all the same. 

Anti-Meran Main Line - For those wondering, the Meran system with 5.e3 Nbd7 6.Bd3 is not seen much at a high level now because 6...dxc4 7.Bxc4 b5 8.Bd3 Bb7 has been worked out to total equality (0.00), and Black even has good alternatives on move 8. So 6.Qc2 is White's main attempt, intending 6...Bd6 7.Bd3 (alternatives exist of course, but they come to 0.00 in the end) 7...0-0 8.0-0 (see diagram below) when Black faces a crossroads, depending on what type of position he wants.

The main line is 8...dxc4 9.Bxc4 b5, which leads to very sharp play after either 10.Be2 or 10.Bd3, but the lines have been virtually worked out to a draw in correspondence (+0.15). That hasn't stopped Grandmasters from being caught out (on either side) not knowing what they are doing, so it's worth pointing out there are alternatives such as 9...a6 (+0.10).

There's also the Classical QGD-inspired 9...e5 (+0.25), which engines are initially a bit dismissive of, but White hasn't demonstrated a good reason why in practice. And then there's 8...e5!? (+0.10), which is a 'beg for a draw' variation, but it's very hard to stop Black succeeding with his pleas. 

5.Bg5 Sidelines - In correspondence play, 5.Bg5 has effectively been worked out to a draw in the Botvinnik Variation (5...dxc4), and one advantage of this from Black's point of view is that, if you are willing to memorize the sharp and complex theory, you could have a theoretically reliable system for life (despite the crazy-looking positions). 

In recent games, the main trend is the Cambridge Springs approach with 5...Nbd7 6.e3 Qa5, which doesn't have quite the theoretical pedigree of 5...dxc4 or 5...h6, but nonetheless is very solid for Black. 7.cxd5 Nxd5 8.Qd2 Bb4 9.Rc1 (see diagram below) peters out to near-equality if Black is somewhat prepared (+0.20).

7.Nd2 is slower-paced but also doesn't promise more than an easier position to play (+0.15). Of course, to play 5...Nbd7 as Black, you also have to ready for the transposition to a Nf3 Exchange QGD with 6.cxd5 exd5. 

Interestingly enough, even something like 5...Nbd7 6.e3 h6 7.Bh4 Be7, which is traditionally thought to be a poor version of the Bg5 Classical QGD, is still hard for White to prove more than a modest edge in (+0.25). However, lines such as 7...g5 8.Bg3 Nh5 (+0.5) are fundamentally unsound and should be dismissed as blitz/rapid experiments, played in the hope of surprising the opponent. 

The Anti-Moscow Gambit - The main line for Black in the Semi-Slav, however, is 5.Bg5 h6, though it has such a massive body of theory from engine games that most top GMs today seem unwilling to learn all the ideas. However, the reward of such effort is that you get excellent winning chances from a very solid foundation.

The Anti-Moscow Gambit with 6.Bh4 dxc4 7.e4 g5 8.Bg3 b5 is essentially an 'improved Botvinnik' where White is already committed to Bg3, though White in turn has a more flexible structure with his pawn still on e4. Whoever knows the theory better here is likely to win the game, but the positions are so complex and messy that all three results are possible in practice. For those who are willing to study a lot of correspondence games and have time to kill on learning deep opening theory, this could be a great choice. 

The Moscow Variation - The 'saner' option for White after 5...h6 is 6.Bxf6 Qxf6 7.e3 (7.Qb3 and other moves quickly come to 0.00), reaching a more strategic battle between White's space advantage and the bishop pair - though it's admittedly a more flexible version for Black with ...c6 instead of, say ...Bxf6 or the bishop already on b4.

In any case, the main line for Black is 7...Nd7 (+0.15) followed by ...dxc4 (after Bd3)/...g6/...Bg7/...0-0 in some order, where Black is ready to meet e4 with ...e5 to strike back in the centre, but can also prepare the ...c5 break. What makes these positions quite attractive is that White can't just sit and do nothing due to Black's bishop pair, but at the same time, the opening of the position may also favour Black, if he can catch up in development. 

For what it's worth, Black is not limited to this move order - he could also play the immediate 7...g6!? (0.00, see diagram below), which is less theoretical than 7...Nd7 but not at all inferior.

Even within ...Nd7, there are other setups, such as with 7...Nd7 8.Be2 Bd6 or 8...Qd8/Be7 (+0.20), where Black can generally hold a solid draw without much trouble. 

Conclusion

As you can imagine, this post took a very long time to write, as there are a very large number of defences to 1.d4, and of course, it takes far longer to type something than to speak it. 

Nonetheless, I trust that this overview of the options has given you a lot more clarity in terms of what system you want to play against 1.d4. Furthermore, for those who do play 1.d4/2.c4 as White, you now know the options at your opponent's disposal, and in turn have a better idea of what variations you may prefer to allow, or avoid.

As a chess theoretician, my perspectives on these different variations hold a certain weight. Of course, nowadays the chess theoretician is more of a messenger, delivering the conclusions of deep engine analysis in a way that makes sense and has practical use to non-professional players (or any professionals they may be coaching/seconding). 

At the same time, I tried my best to share my practical thoughts of the variations, from my own experience. Namely, in which lines the positions are much easier to play for White, where I disagree with the engine's assessments, the general nature of the positions, and whether certain lines are more appropriate as a drawing weapon or in playing for a win. 

Of course, this is just a summary of my knowledge of the 1.d4 options, and I have gone much, much deeper in my own studies to reach these conclusions. If you are rated over 2000, and are interested in working with me to improve your chess as quickly as possible (spending 20% of your time to achieve 80% of the results, rather than 80% of your time to achieve 20% of the results), send me a message at m.me/max.illingworth.16.

As for your thoughts on my conclusions - you are welcome to share them in the comments below! If you have some new idea that could overturn one of these conclusions, it would be an interesting learning opportunity for me as well as the other readers.

Also let me know if you'd like to see a similar post detailing the defences against 1.e4!